Train control system



Aug. 29, 1933. H P. TROMBETTA 1,924,219 7 TRAIN CONTROL SYSTEM Filed June 8, 1932 2 Sheets-Sheet 1 Fig.1

' INVENTOR Harm and D TrombeH'a ATTORNEYS 1933- H. P. TROMBETTA 1,924,219

TRAIN CONTROL SYSTEM Filed June 8, 1932 2 Sheets-Sheet 2 34 z? 28 l j INVENTOR Hermand P Trombefiu WS W ATTORNEYS Patented Aug. 29, 1933 UNITED sTA'rEs iszizie rAre 6 Claims.

My present invention relates to a train control system.

The purpose of this invention is to provide a new and improved train control system and particularly a system wherein a re-set switch used to restore the engineers control of the train is co-operatively connected with or controlled by an air controlled locking device taking its air from some part of the air brake system and to have the parts of said system and particularly said locking device of such form, construction and co-operation with the other parts of the system that the re-set switch will be held in locked position during an automatic application of the air brakes but will be unlocked upon the completion of such automatic application of the brakes.

In the train control systems, as now'used an automatic application of the air brakes is brought about when an engine runs past a closed block 20 signal such application ofthe brakes being automatic in the sense that the air brakes are brought into operation without any action on the part of the engineer and simply by more or less direct operation of the air brakes following the receipt by the proper part of the signal system upon the engine of an impulse, usually electrical, received from a part of the signal system upon the ground. Furthermore, when such an automatic application of the air brake is commenced the engineers control of the brakes is temporarily suspended and remains so suspended until a re-set switch is operated. In practice heretofore, this re-set switch has been located at or near the rear end of the tender back of, the engine and could not be reached by the engineer or fireman without one of them leaving the cab and going along the ground at the side of the tender., Whenthe re-set switch was thus reached the box containing the same would be opened by the engineer and i the re-set switch moved so as to temporarily close one or more electrical circuits that would restore the engineers control of the air brakes and other necessary parts of the engine. The purpose of placing this re-set switch in such an inaccessible place was to insure that thetrain would be brought to a fullstop before the re-set switch would be operated or in other words to prevent thev engineer from regaining control of the train until a full stop of the train had been made. The management of most railroads have required this in order to get a full report from the engineer as to each automatic application of the air brakes.

On the other hand, this construction required heretofore hasbeen recognized as endangering the life or limb of the engineer for the reason that the engine would often be brought to a stop at places where the roadbed would not be safe for the engineer to walk upon,especially at night, or where the train would be too close to other tracks or where the path to be followed by the engineer would be dangerous as when covered by snow, ice or water. Even the steps from the cab to the ground may be dangerous from snow or ice and this danger not be apparent when the engineer starts to go down the steps.

The main purpose of my invention is to overcome the disadvantages of such systems as here tofore used and to provide a system wherein an automatic application of the brakes from the signal system positively locks the re-set switch until the full service application of the air brakes has been accomplished and the train stopped, but then allows the" engineer toagain resume full control ofthe train by operating there-set switch and to have such re-set switch conveniently 10-, cated in the cab of the engine so that it may be operated by the engineer without leaving the cab; and particularlyto provide a locking deviceior said re-set switch whichlocking device holds the re-set switch in locked position until the train has been stopped, but which locking'device then becomes reversed or capable of being re versed so that the engineer may then operate the re-set switch without leaving the cab.

A further particular purpose is to provide a locking device for said re-set switch which is air-.

controlled by air from a suitable part of the air brake system and particularly to provide an aircontrolled locking device which is connected to some portion of the air pipes or air conduits of the air brake system where the pressure or amount of pressure is sharply changed during the application or incident to the application of the air brakes. My purpose in so constructing the locking system is to make sure that the re-set switch will be lockedduring an automatic application of the air brakes and will also become unlocked at the completion of such application of the air brakes. By connecting such locking device thus directly to the air brake system I not only insure the proper locked andfunlocked condition of the locking device at the proper time relative to the operation of the air brakes, but do soby the use of simple mechanism and without requiring other or new sources of power to control the locking device. I

Fig. 1 is a diagrammatic view of the air brake system of 'a'train and showing the actuator 10 applied to the engineers brake. valve 11 whereby through an electric impulse received when the engine passes a block signal set against the engineer the engineers valve is automatically moved to make a service application of the brakes of the train and the engineer is deprived of ordinary control over the air brake system until the train has been brought to a stop and thereafter a re-set switch 12 has its re-set contactor 13 moved manually whereby through electrical connections the engineers brake valve is or may be restored to thecontrol of the engineer. To this system of parts as heretofore commonly used I have added and co-operatively combined a 1ocking device 14 which holds the contactor of the reset switch from motion until the automatic service application of the air brakes has been completed.

Fig. 2 is a top or plan view of one form of a I locking device embodying my invention applied 1 brakes of each car of the train.

to the re-set switch but showing the locking mechanism in unlocked position.

Fig. 3 is a vertical longitudinal sectional view on line 33 ofFig. 2, but showingthe looking device in locking position.

Fig. 4 shows mostly in diagrammatical illustration a second or modified form of my invention, wherein the locking device for the re-set switch is air-controlled bybeing connected to the main brake pipe of the brake system.

. Fig. 5 is a plan view of the contact plates 41, 42 and 42 and a view partly in plan and partly in section of adjacent portions of the device.

Referring to the drawings in a more detailed description, it will be seen that the air brake system for a train shown in Fig. 1 includes a pump 15 ordinarily operated, by steam from the locomotive boiler (not shown) 'and adapted to pump air through pipe 16 into the main reservoirs 17-17. From these main reservoirs the air under high pressure is conducted through pipe 18 to the engineers brake valve 11 and through a pipe 19 branching off from pipe 18 to the distributing valve 20. From the engineers brake valve 11 air may be conducted through the pipe 21 to the main brake pipe 22 of the train. It will be understood that the said brake pipe is connected by pipe 23 to the distributing valve 20 and that the arrangement is such that upon an automatic service application of the brakes through a movement of the actuator 10 the relatively high pressure, say one hundred ten pounds, in the said brake pipe 22 will greatly decrease in amount, resulting in an operation of the distributing valve so as to admit air at an increasing pressure in the brake cylinder pipe 24 leading from the distributing valve 20 to the driver brake cylinders 25-25 and to the truck brake cylinder 26, thus causing the pistons in said driver brake cylinders andtruck brake cylinders to be moved by the increasing air pressure and apply the brakes connected thereto (not shown) to the driver wheels of the locomotive and to the truck wheels of the locomotive. The sharp and continued reduction of air pressure in the pipe 21 and the main brake pipe 22 will in a mannerwell known in the art and not necessary to be described or shown herein in detail cause a movement of the triple valves upon the auxiliary air reservoirsof the respective cars of the train and thereby produce an application of the It Will now be seen that upon automatic service application of the brakes through the operation of the ac' tuator 10 the air pressure in the brake cylinder j pipe 24 rises sharply and strongly to directly apply the brakes upon the locomotive and if desired tosimilarly operate brakes upon the brake cylinder pipe 24 will continue to build up until the brakes are finally set if necessary and the train is brought to a stop. It will also be noted that reversely the air pressure in the brake pipe 22 will constantly run down or decrease until the full service application of the brakes is made upon the cars of the train.

My invention contemplates broadly the use of a locking device for the contactor 13 of the re-set switch '12 whereby said locking device will remain locked during an automatic service application of the brakes, but will become unlocked and release the re-set switch contactor for manual movement after a full automatic service application of the brakes has been effected. This result I accomplish by having the locking device 14 include a cylinder 27 in which is reciprocatingly mounted a piston 28 from which there projects to a point outside the cylinder the piston rod 29 bearing at its free end a yoke 30, the spaced fingers 3l--1 of which straddle the stem 32 of the movable contactor 13 of the re-set switch 12. The yoke 30' is kept from rotation by its lower side engaging a fixed fiat guide 55.

In what I will call the first form of my invention shown specifically in Figs. 2 and 3 and shown diagrammatically in Fig. 1, the locking mechanism and particularly the piston 28 and cylinder 27 are so constructed and arranged and combined with the proper air pipes of the brake system as by connecting the right hand end of the cylinder 27 by suitable pipe 33 to the brake cylinder pipe 24, that air with sharply and constantly increasing pressure is applied'to the right hand face of the piston 28 as seen in Figs. 2

and 3 during an automatic service application 30 so that as long as the piston 28 and yoke 30 are projected to the outer or right hand position as shown in Fig. 3 the stem 32 bearing the movable contactor 13 cannot be moved or pushed down by pressure applied to the head 36 at the top of said stem normally projecting out through the aperture 37 of the cover 38 of the box 39 housing the re-set switch and the locking device. It will be seen, however, that as the automatic service application of the brakes continues to finalfull application the air pressure received from the brake cylinder pipe 24 will increase finally to a point wherethe air pressure upon the right hand face of the piston 28 will overcome the fixed tension of the spring 34 and move the piston 28 to the left and accordingly withdraw the fingers 31 of the yoke 30 from beneath the rib 35 of the stem of the reset switch and to the position shown in Fig. 2. In this position of the parts the engineer, by pressure from his hand or foot(as most convenient according to the location of the parts) applied to the head 36 of the contactor stem, may push the movable. contactor 13 downwardly against the slight tension of spring 40 until the movable contactor 13 engages the diftor 10 into operation. lhe electrical part of the brake system is shown diagrammatically in Fig.

. l but a detailed description is not deemed necessexy as it is already well-known in train control systems of the type to which my improvement is applied and my air controlled device for normally holding the reset switch locked and at the proper time allowing the manual operation of this reset switch by the engineer in the cab does not change the electrical connections heretofore used between the reset switch and the air system of the brakes when the reset switch was purposely placed, at the side or rear of the tender of the locomotive, where it could not be reached by the engineer until the train had come to a stop. Upon the circuits being completed through the depressed movable contactor 13 and the fixed contact plates 41, 42 and 42 and their respective wires, electrically actuated or operated means are moved'or actuated so that the engineers brake valve is restored to the control of the engineer. After a short contact of the movable contactor 13 with the plates 41, 42 and 42 the engineer or fireman removes the pressure from the head 36 of the stem of the re-set switch and the movable portions thereof return to the position shown in Fig. 3 under the impulses of the spring 40 coiled about the guiding pin 47. As the engineer resumes control of the air brake system and moves his air brake valve to releasing position, the air pressure in the brake cylinder pipe 24 is reduced and such reduction continues until the release is accomplished and such reduction is sufficient to reduce the air pressure at the right end of the cylinder 2'7 of the locking device to a point where the coil spring 34 once more moves-the piston 28 and piston rod 29 to the right until the yoke 36 again has its fingers straddling the stem 32 below the rib whereupon the re-set switch is again locked.

It will be understood that one of the direct or indirect results of movement of the contactor 13 against the fixed contact plates of the re-set switch is to cause or allow the electric portion of the electro-pneumatic valve 46 controlled by the circuit wires 48 and 49 leading thereto to open the valve thereof so as to allow the passage of air through the pipe 50 leading from the main pipe 18 to the actuator 10. In this way the actuator is restored to normal position and allows the engineer to again control the engineers brake valve.

It will be understood that more or less elaborate electrical circuits and systems lead from the signal receiver 51 suitably mounted upon a train, usually upon the tender, to the electropneumatic valve 46 by means of the said wires 48 and 49 of the electrical portion of said valve.

A common arrangement of the intermittent inductive auto manual system indicated diagram- 7 matically in Fig. 1 is to have the signal receiver 51 road when such signal system is set to indicate" that the block ahead of the engine is set against the engineer.

In Fig. 4 there is illustrated a second formlof my invention. In this form of my invention the locking device 14' is so constructed as to move from looking position upon the decrease of air pressure in a pipe of the brake system of the train. In this form of my invention the locking member 14 built in the main like the locking member 14 already'described, 'hashowever its piston 28 held forward or locking-position by means of air pressureadmitted to the left hand side of the pistonthrough a pipe 53 connected to the main brake pipe 22 of the air brake system. As already mentioned, the pressure in this brake pipe 22 is normally maintained'at a relatively high pressure, say 110 pounds, and upon an automatic application of the brakes being started the air pressure in this brake pipe 22 is sharply'and progressively reduced in order to bring into action the triple valves controlling the operation of the individual brake systems upon the separate cars of the train. It will be seen accordingly that in the modification shown in Fig. 4: this normal high pressure of the main brake pipe 22 will be continued regularlyand continuously in the chamber of the cylinder 27 to the left of the piston 28 except when a complete and train-stopping automatic application of the air brakes has been brought about. Upon such automatic application of the brakes being started the air pressure in the cylinder 2'? begins to decrease but the decrease is regulated to take place so slowly that the brakes will be on long enough and with sufficient power to always give time to effect a full stop of the train before the air pressure in cylinder 2'! has been reduced-to a suificiently low point to allow the weak-ten: sioned spring 54 bearing against the right-hand side of the, piston 28 to move the piston to the left. When the air pressurein the cylinder decreases to that extent, said spring moves the piston 28 and its piston rod 29' to the left thereby disengaging the yokeSO from the. stem 32' of ie movable contactor 13 or" the re-set switch. It will be understood that the locking yoke 30 will not be disengaged from the stem of the contactor until the full or final completion of the automatic application of thebrakes has been continued long enough tostop the train. Coriv sequently. in this modification 01 my invention as inthe other or first described form the en'- gineer cannot operate the re-set switch after an automatic application of the brake once begins until that automatic application has been completed and the train stopped. In this second form of my invention it will be seen that after the locking yoke 30 has been disengaged from the stem of the contactor the engineer or fireman may make the necessary movement of the contactor against the fixed contact plates 41', 41a

and 42 and thereby enable the said re-set switch to operate through its electrical circuits to ultimately restore the control of the engineers valve of the brake system to the engineer.

In both forms of my invention it will be seen that the locking device is normally held to lock the re-set switch against movement and that the locking device is so connected to some portion of the air brake system wherein a sharp and progressive change of air pressure takes place upon an automatic application of the brakes so that the locking device is retracted from looking position after a complete automatic application of be seen, therefore, that my invention allows the re-set switch to be placed in any convenient position in the engineers cab so that he or the brakeman can reach and operate the re-set switch without leaving the engine and thus the life and limb of the engineer and fireman will be safe-guarded.

At the same time, it will be seen that all the purposes heretofore aimed at by the management of the railroads in placing the re-set switch at such an inaccessible place upon or near the rear end of the tender as to make it impossible to reach the same until the train has been stopped has been accomplished by my invention in that the re-set switch is absolutely locked against any operative movement thereof by the engineer or fireman after an automatic application of the air brakes has been once started, but that such re-set movement of the re-se't switch is promptly and conveniently allowed after the automatic application of the air brakes has been accomplished and the train brought to a stop.

What I claim as new and desire to secure by Let'- ters Patent is:

1. In a train control system the combination of a signal element on the ground, air brakes and air pipes therefor-upon the train including air pipes the pressure in which is changed when the air brakes are applied, means normally operable by'the engineer for controlling said air brakes,

means actuated by said element for automatically bringing the'air brakes into operation and stopping the train and rendering inoperative the engineers control, a re-set switch adapted to restore to operation the engineers control system,

an air-controlled locking device for said re-set switch and conduits operatively connecting said locking device with said changing-pressure air pipes whereby said locking device holds said reset switch locked during an automatic application ically bringing the air brakes into operation and stopping the train and rendering inoperative the engineers control, a re-set switch adapted to restore to operation the engineers control system, an air-controlled locking device for said re-set switch and conduits operatively connecting said locking device with said changing-pressure'air pipes whereby said locking device holds said re-set switch locked during an automatic application of the brakes and unlocks the re-set switch upon the completion of such automatic application.

i 3. In a train control system the combination of a signal element on the ground, air brakes and air pipes therefor upon the train including air pipes the pressure in which is changed when the air brakes are applied, means normally operable by the engineer for controlling said airbrakes, means actuated by said element for automatically bringingthe air brakes into operation and stopping the train and rendering inoperative the.

engineers control, a re-set switch adapted to restore to operation the engineers control systern and a device including a movable member normally locking said re-setswitchfrom operation, said locking device being air-actuated and operatively connected to-said changing-pressure air pipes of the air brakes so that upon said change of pressure in said pipes on the setting of said brakes, said movable member is shifted from looking position.

4. In a train control system the combination of a signal element on the ground, airbrakes and air pipes therefor upon the train including air pipes the pressure in which is changed when the air brakes are applied and changed back change of pressure in said pipes on the setting oi said brakes, said movable member is shifted from looking position, but will return to locking position when thebrakes are released.

5. In combination, a re-set switch adapted to restore an air brake system to the control of the engineer after an automatic application of the air brakes and a locking device for said switch which locking device is operatively connected to a changing-pressure air pipe of the air-brake system so as to lock said re-set switch from move ment upon an automaticapplication of the brakes until the application is completed and then to permit said re-set switch to be moved.

6. In combination, an air brake system for a train including air pipes the pressure in which is changed when the brakes are applied, means normally operable by the engineer forcontrolling said air brakes, means for automatically bringing the brakes into operation and rendering inoperative the engineerscontrol, a re-set switch adapted to restore to operation the engineers control system and a device including a movable member normally locking said re-set switch from operation and operatively connectedv to said changing-pressure air pipes so that :upon completion of the application of the brakes said mov able member is shifted from looking position. 

